N-1March 17, 2026 Wind and Rain Event - Storm Report
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Legend (CHI) Red >50,000 Orange >25,000 Yellow >10,000 Northern Northeast Green <10,000 Valley Eastern Shore Halifax Customers Restored within x hours of Storm Onset South Shore Provincial % Within 6 Hrs 8.85% Within 12 Hrs 46.76% Within 2...
AI summary This table shows the percentage of customers restored within specific timeframes after a storm, with data categorized by region. It highlights the restoration rates for Northern, Northeast, and other areas, indicating that nearly all customers were restored within 48 hours.
SECTION 4: PROVINCIAL HIGHLIGHTS Zone Date/ Time Weather Station Direction (Degrees) Max Wind Gusts (km/h) Temp (°C) Cause Sub-Cause Description Customers Impacted Duration (Hours) Valley 3/17/2026 10:27 Greenwood 180 31 65 16 Tree Contact...
AI summary This section presents a table of outages in Nova Scotia on March 17, 2026, caused by high winds and heavy rain. Each entry includes details such as zone, time, weather station, wind direction, maximum wind gusts, temperature, cause, sub-cause, description, number of customers impacted, and duration of the outage.
SECTION 4: ZONE SUMMARY IMPACT SUMMARY – VALLEY This region experienced heavy rain and wind gusts up to 67 km/h during the event. Restoration of the longest event was delayed due to localized flooding in the area.
AI summary The Valley region experienced heavy rain and wind gusts up to 67 km/h, causing localized flooding that delayed restoration efforts during the event. The impact highlights challenges in service recovery due to extreme weather conditions.
84% Adverse Weather Cause of Outage (CHI) \ elapsed time from first outage event to restoration of last event
AI summary The document highlights that 84% of outages were caused by adverse weather, impacting customers and leading to interruptions in service. Visual representations and a footnote indicate the time elapsed from the first outage event to the restoration of the last event.
Duration Zone Date/ Time Weather Station Direction (Degrees) Wind (km/h) Max Wind Gusts (km/h) Temp (°C) Cause Sub-Cause Description Customers Impacted Duration (Hours) Valley 3/17/2026 9:11 Greenwood 180 26 65 17 Adverse Weather Flood Loc...
AI summary The table details four outage events in the Valley zone on March 17, 2026, caused by adverse weather (flooding) and falling trees. Each entry includes weather conditions, customer impact (1–116 customers), and outage durations (1.82–22.36 hours). The primary causes are tree contacts and flooding, with durations varying significantly between incidents.
SECTION 4: ZONE SUMMARY IMPACT SUMMARY – SOUTH SHORE Cause of Outages (CHI) This region experienced heavy rains with winds reaching 74 km/h. The largest contributor of outages was due to trees contacting the power lines.
AI summary The South Shore region experienced outages caused by heavy rains and winds reaching 74 km/h, with trees contacting power lines being the primary contributor to interruptions.
SECTION 4: ZONE IMPACT SUMMARY – NORTHERN Cause of Outages (CHI) This region experienced heavy rains with winds reaching 74 km/h. A single broken pole caused 97% of the customer hours of impact in this region.
AI summary The Northern region faced severe weather with winds up to 74 km/h, leading to a single broken pole causing 97% of customer hours of interruption (CHI). This highlights the vulnerability of the grid to extreme weather events and the significant impact of infrastructure failures on service reliability.
Outage Summary: Customers Impacted: 770 Customer hours of interruption: 5,249 Full Restoration\ : 12.14 Hours
AI summary An outage affected 770 customers, resulting in 5,249 customer hours of interruption. Full restoration was achieved after 12.14 hours. The summary provides quantitative data on the outage's scope and duration.
SECTION 4: ZONE IMPACT SUMMARY – NORTHEAST This region experienced heavy rains with winds reaching 72 km/h. The largest event in this region contributed 50% of the CHI and was caused by a tree making contact with the primary line.
AI summary The Northeast region experienced severe weather with 72 km/h winds, causing a tree-line collision that led to the largest outage event, contributing 50% of the Customer Hours of Interruption (CHI) in the region.
Duration Zone Date/ Time Weather Station Direction (Degrees ) Wind (km/h) Max Wind Gusts (km/h) Temp (°C) Cause Sub-Cause Description Customers Impacted Duration (Hours) North Eastern 3/17/2026 10:56 Caribou Pt. 190 39 67 14 Tree Contacts...
AI summary Two service outages in the North Eastern zone on 3/17/2026 caused by high winds, heavy rain, and falling trees impacted 585 customers, with durations ranging from 1.58 to 11.45 hours. Both incidents involved tree contact with power lines, triggering recloser operations.
SECTION 4: ZONE SUMMARY IMPACT SUMMARY – METRO Cause of Outages (CHI) This region experienced heavy rains with winds reaching 87 km/h. This leading cause of outages in this region was due to trees contacting the power lines.
AI summary The Metro region experienced heavy rains and winds up to 87 km/h, with trees contacting power lines identified as the leading cause of outages. This weather event highlights infrastructure vulnerability to external environmental factors.
Outage Summary: Customers Impacted: 60,212 Customer hours of interruption: 174,506 Full Restoration\ : 37.32 Hours
AI summary An outage affected 60,212 customers, totaling 174,506 customer hours of interruption. Full restoration took 37.32 hours, highlighting significant service disruption and recovery time metrics.
SECTION 4: ZONE SUMMARY IMPACT SUMMARY – EASTERN SHORE This region was significantly impacted by strong winds causing trees to make contact with the power lines. This region saw winds exceeding warning levels, reaching 83 km/h.
AI summary The Eastern Shore region experienced significant power line disruptions due to strong winds exceeding 83 km/h, causing trees to make contact with infrastructure. This highlights the impact of severe weather on grid reliability and service continuity in the area.
Outage Summary: Customers Impacted: 610 Customer hours of interruption: 2,637 Full Restoration\ : 28.13 Hours
AI summary An outage impacted 610 customers, resulting in 2,637 customer hours of interruption. Full restoration was achieved after 28.13 hours, highlighting the duration and scope of the service disruption.
SECTION 4: ZONE IMPACT SUMMARY – CAPE BRETON WEST This region experienced wind gusts up to 83 km/h during the weather event. The largest contributor to outage was due to trees contacting the power lines.
AI summary The Cape Breton West region experienced wind gusts up to 83 km/h, with tree-line contact being the primary cause of power outages during the weather event.
Outage Summary: Customers Impacted: 2,500 Customer hours of interruption: 4,723 Full Restoration\ : 18.69 Hours
AI summary The outage summary reports 2,500 customers impacted with 4,723 customer hours of interruption. Full restoration was achieved after 18.69 hours, highlighting the duration of service disruption and the scale of customer impact during the incident.
Cause of Outages (CHI) Adverse Weather Cause of Outage (CHI) \ elapsed time from first outage event to restoration of last event
AI summary The document discusses adverse weather as a primary cause of outages (CHI), referencing figures that illustrate the relationship between weather events and outage durations. It includes a metric for elapsed time from the first outage event to the restoration of the last event, highlighting system reliability challenges.
SECTION 4: ZONE IMPACT SUMMARY – CAPE BRETON EAST This region was impacted by high winds, reaching a peak of 85 km/h. Tree contacts and a loss of supply event were the largest contributors to outages in the region.
AI summary The Cape Breton East region experienced outages primarily due to high winds (peaking at 85 km/h) causing tree contacts and a loss of supply event, which were the largest contributors to power disruptions in the area.
SECTION 4: ZONE IMPACT SUMMARY – CAPE BRETON EAST TOP TWO EVENTS BY DURATION & CUSTOMER IMPACT
AI summary Section 4 presents a zone impact summary for Cape Breton East, highlighting the top two events by duration and customer impact. The section focuses on analyzing interruptions and their effects on customers, though specific details of the events are not provided in the text.
SECTION 6: LESSONS LEARNED - Tree contacts were the dominant driver of outages across all regions, reinforcing the importance of ongoing targeted vegetation management and continued focus on areas with high exposure and historical tree-rel...
AI summary Tree-related outages were the primary cause of interruptions, emphasizing the need for targeted vegetation management and focus on high-risk areas. Regional variability in outage concentration highlights the necessity of incorporating localized conditions into planning and response strategies.
ELECTRICITY CANADA DEFINITIONS CI = Customer Interruptions Total number of customers without power CHI = Customer Hours of Interruption Combination of customers and duration SAIFI = Average Outage Frequency Customer interruptions / # of cu...
AI summary Defines key metrics for power outage analysis: CI (Customer Interruptions), CHI (Customer Hours of Interruption), SAIFI (Average Outage Frequency), SAIDI (Average Outage Duration), and CAIDI (Average Outage Duration for interrupted customers), including formulas for calculation.
Unknown/other Interruptions with no apparent cause or reason identified that could have contributed to the outage
AI summary The text references interruptions with no identifiable cause, highlighting challenges in outage analysis. Metrics like CHI, CI, SAIFI, SAIDI, and CAIDI are contextually relevant for assessing service reliability and outage impact.
Loss of supply Interruptions due to problem in the bulk electricity system (transmission)
AI summary The text discusses interruptions caused by issues in the bulk electricity system, specifically within the transmission network, highlighting concerns related to system reliability and outage management.
Tree contacts Interruptions caused by trees or tree limbs contacting energized circuits
AI summary The document discusses power outages caused by tree contacts with energized circuits, referencing metrics like CHI, CI, SAIFI, SAIDI, and CAIDI to quantify interruption impacts. It highlights the need for addressing vegetation management to improve system reliability and reduce customer interruptions.
Lightning Interruptions due to lightning strike on energized circuits
AI summary The text discusses power interruptions caused by lightning strikes on energized circuits, highlighting a specific cause of service disruptions in the electricity grid.
Defective equipment Interruptions resulting from equipment failures
AI summary The document discusses interruptions caused by equipment failures, highlighting their impact on service reliability. Metrics like SAIDI, SAIFI, and CAIDI are relevant to analyzing outage frequency and duration, though not explicitly mentioned in the provided text.
Adverse environment Interruptions due to equipment being subjected to abnormal environmental conditions (e.g. Salt spray, contamination, humidity, corrosion, vibration, fire, or flooding)
AI summary The text outlines interruptions caused by equipment exposure to adverse environmental conditions such as salt spray, contamination, humidity, corrosion, vibration, fire, and flooding, highlighting their impact on service reliability.
Human element Interruptions due to errors of utility staff in construction, maintenance, or operations
AI summary The text highlights service interruptions caused by human errors in utility staff activities related to construction, maintenance, or operations, emphasizing the impact of such errors on reliability and service quality.
Foreign interference Interruptions due to external contacts beyond the control of the utility (e.g. Birds, animals, vehicles, dig-ins, or other foreign objects) 2 7
AI summary The document discusses interruptions caused by external factors beyond the utility's control, such as birds, animals, vehicles, dig-ins, and foreign objects. These are categorized as 'foreign interference' in the context of system reliability and outage management.